Personal computers have internal hard disk drives and are capable of connection to peripheral mass storage media. For example, the Macintosh.RTM. computer manufactured by Apple.RTM. Computer, Inc. in Cupertino, Calif., is capable of functioning in cooperation with as many as six peripheral storage media connected in a small computer system interface (SCSI) bus chain. The storage media include hard disk, magnetic tape, magneto-optical, SyQuest.TM., and DAT drive modules. These media are typically packaged as cartridge-shaped modules. Because there are potentially seven peripherals available for connection to a SCSI bus, several storage module assembly configurations have been attempted to reduce the physical space occupied by the peripheral devices and facilitate their use in accomplishing a computational task.
One such assembly is the SmartStack.TM. drive system offered by Mirror Technologies of St. Paul, Minn. The SmartStack.TM. system can accommodate seven SmartModule.TM. drive modules in a vertical stack on top of a SmartSource.TM. power base. These modules can include the SyQuest.TM. 105MB drive, 127MB-1.2GB hard drive, optical drive, and DAT drive modules. Each SmartModule.TM. has matable complementary electrical connectors on its respective upper and lower surfaces. To add peripheral storage capacity, a user removes a top cover from the stack and snaps the bottom connector of an additional SmartModule.TM. onto the top connector of the top SmartModule.TM. of the stack and replaces the top cover on the upper surface of the just added SmartModule.TM.. There are no cables interconnecting the SmartModules.TM. and SmartSource.TM. power base in the stack.
The SmartStack.TM. system suffers from the disadvantage of requiring a user to disassemble the stack whenever the user wishes to rearrange the peripherals or remove one of them from the stack.
U.S. Pat. No. 4,682,833 of Ferchau et al. describes a storage system for an array of disk drives each of which is carried in a universal slidable carrier drawer that when closed is automatically electrically connected to a matable connector positioned within the storage system. The storage system includes a unitary cabinet that is partitioned to receive multiple pairs of the drawers positioned side-by-side and arranged in a vertical stack. Each drawer is adapted to receive a disk drive module that can be maintained by pulling out the drawer for access to or removal of the drive module.
U.S. Pat. No. 4,833,544 of Dalziel et al. describes a unitary storage system having a receptacle for each of two portable hard disk drive modules. Each receptacle includes a mechanism for transporting the disk drive module from a module load position to a module operating position and from the module operating position to a module unload position. Movement of the module between these positions is under machine control. The receptacles are arranged so that the modules fit into the system in a bookshelf-type arrangement.
The Ferchau et al. and Dalziel et al. systems are unexpandable unitary structures and, therefore, suffer from the disadvantage of occupying the same amount of space irrespective of the number of disk drives installed or in use.
U.S. Pat. No. 4,530,066 of Ohwaki et al. describes a personal computer that is capable of having its functional capabilities expanded. The computer includes a power section and a main signal processing section that are mechanically connected for relative sliding movements between closely adjacent positions and spread-apart positions. The spread-apart positions define a space between the power and main signal processing sections to accommodate at least one additional signal processing or handling section by which the functional capabilities of the personal computer are expanded. Such additional sections typically include at least one disk drive mechanism. Long screws extending through the housings for the power and signal processing sections rigidly secure them together in an assembly from which any one of the signal processing sections is not readily removable. Thus, a user must partly take apart the assembly to expand or decrease the functional capability of the personal computer.